An attempt has been made to provide a control device for a vehicular automatic transmission as described below. The control device includes shift control means operative to cause the automatic transmission to automatically switch a gear position within a range of a maximum shift-width based on a vehicle condition by referring to a preliminarily stored shifting diagram when an automatic shift mode is set. When a manual shift mode is set, the gear positions of the automatic transmission are switched to plural ranges in which a lower speed gear position lower in speed than that of the uppermost gear position in the range of the maximum shift-width is set as an uppermost gear position, one by one for each manual shift operation of a shift operation device, or they are switched one by one for each manual shift operation of the shift operation device. When a high oil-temperature state is present in which a working oil temperature in the automatic transmission exceeds a predetermined value, the manual shift mode is inhibited while a mode is automatically switched to the automatic shift mode. Shift control devices for vehicular automatic transmissions, disclosed in following Patent Publications 1 and 2, correspond to such a control device mentioned above.    [Patent Publication 1] Japanese Patent Publication No. 2007-170620    [Patent Publication 2] Japanese Patent Publication No. 11-311332
With the control device for the vehicular automatic transmission disclosed in Patent Publication 1, if working oil in the automatic transmission lies at a high temperature, the shifting is executed to a gear position selected in the manual shift mode with a further increasing frequency of downshifts than that of downshifts executed when working oil in the automatic transmission lies at a usual temperature. With the control device for the vehicular automatic transmission disclosed in Patent Publication 2, further, when the working oil temperature in the automatic transmission exceeds an appropriate range preliminary set, an upshift is commanded to a driver to automatically execute the upshift upon no initiation of such an upshift.
With the conventional control devices for the vehicular automatic transmissions set forth above, under a circumstance where temperature of the working oil in the automatic transmission exceeds a predetermined value and an accelerator pedal of a vehicle is depressed, the manual shift mode is sustained and the working oil temperature is lowered. To this end, for a manual shift mode of a so-called shift-range hold type, executing an automatic up-range control is considered in which a shift range of the automatic transmission is automatically up-ranged to the range of the maximum shift-width, and a down-range is inhibited. For another manual shift mode of a so-called gear-position hold type, executing an automatic upshift control is considered in which a gear position of the automatic transmission is automatically switched to the maximum speed gear position and the downshift is inhibited. With such controls, no attempt is made to positively switch the gear position of the automatic transmission to a low speed gear position. This results in a decrease in rotation speed of an input-side rotary member of the automatic transmission, thereby suppressing an temperature increase of the working oil due to the stirring of working oil.
In a vehicle including an automatic transmission arranged to execute the automatic up-range control or the automatic upshift control, however regarding the manual shift operation in the manual shift mode, there are drawbacks such as the manual shift operation becomes cumbersome and complicated, and favorable acceleration response can be hardly obtained. With a multi-gear positions automatic transmission, for instance, obtaining an engine braking is attempted during the vehicle running at a relatively low speed, after the automatic up-range control or the automatic upshift control is executed. In such a case, the downshift operations need to be repeatedly executed after depression-back of the accelerator pedal, until the shift range or the gear position of the automatic transmission reaches the shift range or the gear position in which the adequate engine braking can be obtained at the maximum shift-width range or the highest-speed gear position.
In the automatic transmission having the manual shift mode of the gear-position hold type, further, obtaining a drive force is attempted during a continuing depressive operation of the accelerator pedal after execution of the automatic upshift control. In this case, the downshift is inhibited as set forth above, and even when the vehicle lies in a speed range available to run at a low speed gear position, the vehicle can run only at the highest speed gear position. In the automatic transmission having the manual shift mode of the so-called shift-range hold type (upper limit gear position determining system), moreover, obtaining a drive force is attempted during the continuing depressive operation of the accelerator pedal after execution of the automatic upshift control. In this case, since the downshift is inhibited as set forth above, the vehicle can run only at the maximum shift-width range.